Arsenic Poisoning (cont.)

Charles Patrick Davis, MD, PhD

Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

What is arsenic?

Arsenic is a grey-appearing chemical element (atomic number 33, symbol As in
the periodic table) also termed a metalloid. Arsenic can exist in a metallic
state in three forms (yellow, black, and gray; with gray predominating) and in
ionic forms. Arsenic is considered to be a heavy metal, and arsenic toxicity
shares some features with poisonings by other heavy metals. Historically,
arsenic has been used as a medicinal agent, a pigment, a pesticide, and an agent
with intent to harm (use with criminal intent). Up until 2003, arsenic (in the
form of chromated copper arsenate) was used in the US as a treatment to prevent
insect infestation of wood used in building. In 2003 the use of this compound
was banned by the US Environmental Protection Agency.

Arsenic is mixed with
copper or lead to strengthen alloys containing these materials. Arsenic and some
of its compounds react with proteins, mainly the thiol portions, and uncouples
the process of oxidative phosphorylation, thus inactivating most cellular
functions. Consequently, arsenic and some of the substances it combines with are
deadly poisons to most biologic systems, except for a few bacterial species.
Arsenic is used in making insecticides and weed killers. Arsenic is also thought
to be carcinogenic, meaning that it has the potential to
cause cancer.

Arsenic
can be found as a contaminant in food and water sources. Shellfish and other
seafood, as well as fruits, vegetables, and rice; are the foods most commonly
contaminated. Arsenic poisoning typically occurs as a result of industrial
exposure, from contaminated wine or illegally distilled spirits, or in cases of
malicious intent.